Order isomorphisms and bounds. #
theorem
OrderIso.upperBounds_image
{α : Type u_1}
{β : Type u_2}
[Preorder α]
[Preorder β]
(f : α ≃o β)
{s : Set α}
:
upperBounds (⇑f '' s) = ⇑f '' upperBounds s
theorem
OrderIso.lowerBounds_image
{α : Type u_1}
{β : Type u_2}
[Preorder α]
[Preorder β]
(f : α ≃o β)
{s : Set α}
:
lowerBounds (⇑f '' s) = ⇑f '' lowerBounds s